Use “must” to show that you think something is probably true. Use “might” or “could” to show that you think something is possibly true. Use “can’t” to show that you are almost sure something is not true.

5. I can’t find my backpack. It ___________ must / might be still at school. must 6. The photo __________ be Lu’s. Those are his parents. can’t 7. The red bicycle ___________ be Hu’s. She has a blue bicycle. might / could be my aunt’s or 8. This ticket ___________ uncle’s. They’re both going to the concert.
情态动词must, might, could, can’t表示推 测，后面都接动词原形，都可以表示对现 在情况的揣测和推断，但他们含义有所不 同。
must 一定，肯定 (100%的可能性)
might, could有可能，也许 (20%－ 80%的可能性)
can’t 不可能，不会 (可能性几乎为零)
5. It ________ must be Linda’s schoolbag.
Bob: Hey, look! Whose schoolbag do you think this is? Anna: I don’t know. Look, here’s a school T-shirt. Bob: Well then, the person must go to our school. Oh! Here is a hair band, so the person can’t be a boy. Anna: It could be Mei’s hair band. She has long hair. Bob: Or the hair band might belong to Linda. She was at the picnic, wasn’t she? Anna: Yes, she was. But then the schoolbag could belong to Rita. She’s always forgetting things. Bob: Oh, look! Tennis balls. Anna: Then it must be Linda’s schoolbag. She has long hair and she’s on the tennis team. Bob: You’re right!
The dictionary must be mine. It has my name on it. The CD might / could belong to Tony because he likes listening to pop music. The hair band can’t be Tom’s. After all, he is boy!
Whose … is it?
It must be …
Li Mei Wang Fang
It must be …
It might be …
They might be …
2a Bob and Anna found a schoolbag at the park. Listen and write down the things in the schoolbag.
No. She thinks her friends must have picked it up.
Read after the tape and then roleplay the conversation.
Linda: Mom, I’m in, really worried. attend, join, join take part in都有“参加” Mom: Why? What’s wrong? 的意思。区别是： Linda: I主要指“到场”或“出席”会议、宴会、 can’t find my schoolbag. attend 典礼、仪式等。 Mom: Well, where did you last put it? join指参加某团体或组织成为其中一员或参加 Linda: I can’t remember! I attended a concert 活动,是非正式用语。 yesterday so it might still be in the music attend v. 出席；参加 join in表示“加入；参加 (某种活动)”，in之后 hall. Children school. 儿童必须上学。 接名词或must v.-ingattend 形式；表示“参加某人的某种活 Mom: Do you have anything valuable in your I动”时，可用 promised to attend the show. 我答应去观看文艺演出。 join sb. in (doing) sth. 。 schoolbag? take were part in 指参加一项工作 , 在其中分担一部 They sent to the hospital to attend Linda: No, just my books, my pink hair band 分 , 也指参加活动并积极工作。 short-term training courses. and some tennis balls.
A 3. In competition, as in life, you _______ not always win. A. may B. shall C. must
B 4. In Britain, you ____ be 18 if you want to drive a car. A. can B. must C. may D. might
Make a conversation, using 2d as a model.
Section A 2a — 2d
Section A 1b
Girl 1: Whose volleyball is this? Boy 1: It must be Carla’s. She loves volleyball. Girl 1: How about this toy truck? Girl 2: Hmm… that toy truck must belong to Jane’s little brother. He was the only little kid at the picnic. And the magazine must belong to Deng Wen. He loves rabbits. Boy 1: Oh, look, someone left a book. Girl 2: That book must be Mary’s. J.K. Rowling is her favorite writer. Girl 1: OK… and how about this CD? Girl 2: Hmm… The CD must belong to Grace. She always listens to pop music.
1. The person ________ must go to our school. 2. The person ________ can’t be a boy.
3. It ________ could be Mei’s hair band.
might belong to Linda. 4. The hair band _______
Fill in the blanks with must, might, could or can’t.
1. The notebook ___________ must/might be Ming’s. It was on her desk. can’t be Carol’s. She 2. The homework ________ wasn’t at school today. might/could be John’s or 3. The soccer ball ____________ Tony’s. They both play soccer, don’t they? must be Li Ying’s. 4. The French book _________ She’s the only who is studying French.
2d Read and answer the questions.
1. Why is Linda worried?
Because she can’t find her schoolbag.
2. What are there in her schoolbag? Her books, her pink hair band and some tennis balls. 3. Does Linda think her schoolbag is lost? Why?
A 1. — Is that your teacher? — That _____ be Mr. Wang. He has gone to Japan with his wife. A. can’t B. mustn’t C. may not C 2. －You _____ be happy with the strong public support you’ve received. －Yes, you’re right. I’m really excited. A. may B. can C. must D. need